/*
silverPDF is sponsored by Aleyant Systems (http://www.aleyant.com)

silverPDF is based on PdfSharp (http://www.pdfsharp.net) and iTextSharp (http://itextsharp.sourceforge.net)

Developers: Ai_boy (aka Oleksii Okhrymenko)

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above information and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR SPONSORS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

*/
#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

using System;
using System.Diagnostics;
using System.Runtime.InteropServices;
using System.ComponentModel;
using System.IO;
#if GDI
using System.Drawing;
using System.Drawing.Drawing2D;
using System.Drawing.Imaging;
#endif
#if WPF
using System.Windows.Media;
#endif
using PdfSharp.Internal;
using PdfSharp.Drawing.Pdf;
using PdfSharp.Fonts.TrueType;
using PdfSharp.Pdf;
using PdfSharp.Pdf.IO;
using PdfSharp.Pdf.Advanced;
using PdfSharp.Pdf.Filters;
using PdfSharp.Pdf.Internal;

namespace PdfSharp.Drawing
{
  /// <summary>
  /// Represents a graphical object that can be used to render retained graphics on it.
  /// In GDI+ it is represented by a Metafile, in WPF by a DrawingVisual, and in PDF by a Form XObjects.
  /// </summary>
  public class XForm : XImage, IContentStream
  {
    internal enum FormState
    {
      /// <summary>
      /// The form is an imported PDF page.
      /// </summary>
      NotATemplate,

      /// <summary>
      /// The template is just created.
      /// </summary>
      Created,

      /// <summary>
      /// XGraphics.FromForm() was called.
      /// </summary>
      UnderConstruction,

      /// <summary>
      /// The form was drawn at least once and is 'frozen' now.
      /// </summary>
      Finished,
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="XForm"/> class.
    /// </summary>
    protected XForm()
    { }

#if GDI
    /// <summary>
    /// Initializes a new instance of the XForm class such that it can be drawn on the specifed graphics
    /// object.
    /// </summary>
    /// <param name="gfx">The graphics object that later is used to draw this form.</param>
    /// <param name="size">The size in points of the form.</param>
    public XForm(XGraphics gfx, XSize size)
    {
      if (gfx == null)
        throw new ArgumentNullException("gfx");
      if (size.width < 1 || size.height < 1)
        throw new ArgumentNullException("size", "The size of the XPdfForm is to small.");

      this.formState = FormState.Created;
      //this.templateSize = size;
      this.viewBox.width = size.width;
      this.viewBox.height = size.height;

      // If gfx belongs to a PdfPage also create the PdfFormXObject
      if (gfx.PdfPage != null)
      {
        this.document = gfx.PdfPage.Owner;
        this.pdfForm = new PdfFormXObject(this.document, this);
        PdfRectangle rect = new PdfRectangle(new XPoint(), size);
        this.pdfForm.Elements.SetRectangle(PdfFormXObject.Keys.BBox, rect);
      }
    }
#endif

#if GDI
    /// <summary>
    /// Initializes a new instance of the XForm class such that it can be drawn on the specifed graphics
    /// object.
    /// </summary>
    /// <param name="gfx">The graphics object that later is used to draw this form.</param>
    /// <param name="width">The width of the form.</param>
    /// <param name="height">The height of the form.</param>
    public XForm(XGraphics gfx, XUnit width, XUnit height)
      : this(gfx, new XSize(width, height))
    { }
#endif

    /// <summary>
    /// Initializes a new instance of the <see cref="XForm"/> class that represents a page of a PDF document.
    /// </summary>
    /// <param name="document">The PDF document.</param>
    /// <param name="viewBox">The view box of the page.</param>
    public XForm(PdfDocument document, XRect viewBox)
    {
      if (viewBox.width < 1 || viewBox.height < 1)
        throw new ArgumentNullException("viewBox", "The size of the XPdfForm is to small.");
      // I must tie the XPdfForm to a document immediately, because otherwise I would have no place where
      // to store the resources.
      if (document == null)
        throw new ArgumentNullException("document", "An XPdfForm template must be associated with a document at creation time.");

      this.formState = FormState.Created;
      this.document = document;
      this.pdfForm = new PdfFormXObject(document, this);
      //this.templateSize = size;
      this.viewBox = viewBox;
      PdfRectangle rect = new PdfRectangle(viewBox);
      this.pdfForm.Elements.SetRectangle(PdfFormXObject.Keys.BBox, rect);
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="XForm"/> class that represents a page of a PDF document.
    /// </summary>
    /// <param name="document">The PDF document.</param>
    /// <param name="size">The size of the page.</param>
    public XForm(PdfDocument document, XSize size)
      : this(document, new XRect(0, 0, size.width, size.height))
    {
      ////if (size.width < 1 || size.height < 1)
      ////  throw new ArgumentNullException("size", "The size of the XPdfForm is to small.");
      ////// I must tie the XPdfForm to a document immediately, because otherwise I would have no place where
      ////// to store the resources.
      ////if (document == null)
      ////  throw new ArgumentNullException("document", "An XPdfForm template must be associated with a document.");

      ////this.formState = FormState.Created;
      ////this.document = document;
      ////this.pdfForm = new PdfFormXObject(document, this);
      ////this.templateSize = size;
      ////PdfRectangle rect = new PdfRectangle(new XPoint(), size);
      ////this.pdfForm.Elements.SetRectangle(PdfFormXObject.Keys.BBox, rect);
    }

    /// <summary>
    /// Initializes a new instance of the <see cref="XForm"/> class that represents a page of a PDF document.
    /// </summary>
    /// <param name="document">The PDF document.</param>
    /// <param name="width">The width of the page.</param>
    /// <param name="height">The height of the page</param>
    public XForm(PdfDocument document, XUnit width, XUnit height)
      : this(document, new XRect(0, 0, width, height))
    { }

    /// <summary>
    /// This function should be called when drawing the content of this form is finished.
    /// The XGraphics object used for drawing the content is disposed by this function and 
    /// cannot be used for any further drawing operations.
    /// PDFsharp automatically calls this function when this form was used the first time
    /// in a DrawImage function. 
    /// </summary>
    public void DrawingFinished()
    {
      if (this.formState == FormState.Finished)
        return;

      if (this.formState == FormState.NotATemplate)
        throw new InvalidOperationException("This object is an imported PDF page and you cannot finish drawing on it because you must not draw on it at all.");

      Finish();
    }

    /// <summary>
    /// Called from XGraphics constructor that creates an instance that work on this form.
    /// </summary>
    internal void AssociateGraphics(XGraphics gfx)
    {
      if (this.formState == FormState.NotATemplate)
        throw new NotImplementedException("The current version of PDFsharp cannot draw on an imported page.");

      if (this.formState == FormState.UnderConstruction)
        throw new InvalidOperationException("An XGraphics object already exists for this form.");

      if (this.formState == FormState.Finished)
        throw new InvalidOperationException("After drawing a form it cannot be modified anymore.");

      Debug.Assert(this.formState == FormState.Created);
      this.formState = FormState.UnderConstruction;
      this.gfx = gfx;
    }
    internal XGraphics gfx;

    /// <summary>
    /// Disposes this instance.
    /// </summary>
    protected override void Dispose(bool disposing)
    {
      base.Dispose(disposing);
    }

    /// <summary>
    /// Sets the form in the state FormState.Finished.
    /// </summary>
    internal virtual void Finish()
    {
#if GDI
      if (this.formState == FormState.NotATemplate || this.formState == FormState.Finished)
        return;

      if (this.gfx.metafile != null)
        this.gdiImage = this.gfx.metafile;

      Debug.Assert(this.formState == FormState.Created || this.formState == FormState.UnderConstruction);
      this.formState = FormState.Finished;
      this.gfx.Dispose();
      this.gfx = null;

      if (this.pdfRenderer != null)
      {
        //this.pdfForm.CreateStream(PdfEncoders.RawEncoding.GetBytes(this.pdfRenderer.GetContent()));
        this.pdfRenderer.Close();
        Debug.Assert(this.pdfRenderer == null);

        if (this.document.Options.CompressContentStreams)
        {
          this.pdfForm.Stream.Value = Filtering.FlateDecode.Encode(this.pdfForm.Stream.Value);
          this.pdfForm.Elements["/Filter"] = new PdfName("/FlateDecode");
        }
        int length = this.pdfForm.Stream.Length;
        this.pdfForm.Elements.SetInteger("/Length", length);
      }
#endif
#if WPF
#endif
    }

    /// <summary>
    /// Gets the owning document.
    /// </summary>
    internal PdfDocument Owner
    {
      get { return this.document; }
    }
    PdfDocument document;

    /// <summary>
    /// Gets the color model used in the underlying PDF document.
    /// </summary>
    internal PdfColorMode ColorMode
    {
      get
      {
        if (this.document == null)
          return PdfColorMode.Undefined;
        return this.document.Options.ColorMode;
      }
    }

    /// <summary>
    /// Gets a value indicating whether this instance is a template.
    /// </summary>
    internal bool IsTemplate
    {
      get { return this.formState != FormState.NotATemplate; }
    }
    internal FormState formState;

    /// <summary>
    /// Get the width of the page identified by the property PageNumber.
    /// </summary>
    [Obsolete("Use either PixelWidth or PointWidth. Temporarily obsolete because of rearrangements for WPF. Currently same as PixelWidth, but will become PointWidth in future releases of PDFsharp.")]
    public override double Width
    {
      //get { return this.templateSize.width; }
      get { return this.viewBox.Width; }
    }

    /// <summary>
    /// Get the width of the page identified by the property PageNumber.
    /// </summary>
    [Obsolete("Use either PixelHeight or PointHeight. Temporarily obsolete because of rearrangements for WPF. Currently same as PixelHeight, but will become PointHeight in future releases of PDFsharp.")]
    public override double Height
    {
      //get { return this.templateSize.height; }
      get { return this.viewBox.height; }
    }

    /// <summary>
    /// Get the width in point of this image.
    /// </summary>
    public override double PointWidth
    {
      //get { return this.templateSize.width; }
      get { return this.viewBox.width; }
    }

    /// <summary>
    /// Get the height in point of this image.
    /// </summary>
    public override double PointHeight
    {
      //get { return this.templateSize.height; }
      get { return this.viewBox.height; }
    }

    /// <summary>
    /// Get the width of the page identified by the property PageNumber.
    /// </summary>
    public override int PixelWidth
    {
      //get { return (int)this.templateSize.width; }
      get { return (int)this.viewBox.width; }
    }

    /// <summary>
    /// Get the height of the page identified by the property PageNumber.
    /// </summary>
    public override int PixelHeight
    {
      //get { return (int)this.templateSize.height; }
      get { return (int)this.viewBox.height; }
    }

    /// <summary>
    /// Get the size of the page identified by the property PageNumber.
    /// </summary>
    public override XSize Size
    {
      //get { return this.templateSize; }
      get { return this.viewBox.Size; }
    }
    //XSize templateSize;

    /// <summary>
    /// Gets the view box of the form.
    /// </summary>
    public XRect ViewBox
    {
      get { return this.viewBox; }
    }
    XRect viewBox;

    /// <summary>
    /// Gets 72, the horizontal resolution by design of a form object.
    /// </summary>
    public override double HorizontalResolution
    {
      get { return 72; }
    }

    /// <summary>
    /// Gets 72 always, the vertical resolution by design of a form object.
    /// </summary>
    public override double VerticalResolution
    {
      get { return 72; }
    }

    /// <summary>
    /// Gets or sets the bounding box.
    /// </summary>
    public XRect BoundingBox
    {
      get { return this.boundingBox; }
      set { this.boundingBox = value; }  // TODO: pdfForm = null
    }
    XRect boundingBox;

    /// <summary>
    /// Gets or sets the transformation matrix.
    /// </summary>
    public virtual XMatrix Transform
    {
      get { return this.transform; }
      set
      {
        if (this.formState == FormState.Finished)
          throw new InvalidOperationException("After a XPdfForm was once drawn it must not be modified.");
        this.transform = value;
      }
    }
    internal XMatrix transform = XMatrix.Identity;

    internal PdfResources Resources
    {
      get
      {
        Debug.Assert(IsTemplate, "This function is for form templates only.");
        return PdfForm.Resources;
        //if (this.resources == null)
        //  this.resources = (PdfResources)this.pdfForm.Elements.GetValue(PdfFormXObject.Keys.Resources, VCF.Create); // VCF.CreateIndirect
        //return this.resources;
      }
    }
    //PdfResources resources;

    /// <summary>
    /// Implements the interface because the primary function is internal.
    /// </summary>
    PdfResources IContentStream.Resources
    {
      get { return Resources; }
    }

    /// <summary>
    /// Gets the resource name of the specified font within this form.
    /// </summary>
    internal string GetFontName(XFont font, out PdfFont pdfFont)
    {
      Debug.Assert(IsTemplate, "This function is for form templates only.");
      pdfFont = this.document.FontTable.GetFont(font);
      Debug.Assert(pdfFont != null);
      string name = Resources.AddFont(pdfFont);
      return name;
    }

    string IContentStream.GetFontName(XFont font, out PdfFont pdfFont)
    {
      return GetFontName(font, out pdfFont);
    }

    /// <summary>
    /// Tries to get the resource name of the specified font data within this form.
    /// Returns null if no such font exists.
    /// </summary>
    internal string TryGetFontName(string idName, out PdfFont pdfFont)
    {
      Debug.Assert(IsTemplate, "This function is for form templates only.");
      pdfFont = this.document.FontTable.TryGetFont(idName);
      string name = null;
      if (pdfFont != null)
        name = Resources.AddFont(pdfFont);
      return name;
    }

    /// <summary>
    /// Gets the resource name of the specified font data within this form.
    /// </summary>
    internal string GetFontName(string idName, byte[] fontData, out PdfFont pdfFont)
    {
      Debug.Assert(IsTemplate, "This function is for form templates only.");
      pdfFont = this.document.FontTable.GetFont(idName, fontData);
      //pdfFont = new PdfType0Font(Owner, idName, fontData);
      //pdfFont.Document = this.document;
      Debug.Assert(pdfFont != null);
      string name = Resources.AddFont(pdfFont);
      return name;
    }

    string IContentStream.GetFontName(string idName, byte[] fontData, out PdfFont pdfFont)
    {
      return GetFontName(idName, fontData, out pdfFont);
    }

    /// <summary>
    /// Gets the resource name of the specified image within this form.
    /// </summary>
    internal string GetImageName(XImage image)
    {
      Debug.Assert(IsTemplate, "This function is for form templates only.");
      PdfImage pdfImage = this.document.ImageTable.GetImage(image);
      Debug.Assert(pdfImage != null);
      string name = Resources.AddImage(pdfImage);
      return name;
    }

    /// <summary>
    /// Implements the interface because the primary function is internal.
    /// </summary>
    string IContentStream.GetImageName(XImage image)
    {
      return GetImageName(image);
    }

    internal PdfFormXObject PdfForm
    {
      get
      {
        Debug.Assert(IsTemplate, "This function is for form templates only.");
        if (this.pdfForm.Reference == null)
          this.document.irefTable.Add(this.pdfForm);
        return this.pdfForm;
      }
    }

    /// <summary>
    /// Gets the resource name of the specified form within this form.
    /// </summary>
    internal string GetFormName(XForm form)
    {
      Debug.Assert(IsTemplate, "This function is for form templates only.");
      PdfFormXObject pdfForm = this.document.FormTable.GetForm(form);
      Debug.Assert(pdfForm != null);
      string name = Resources.AddForm(pdfForm);
      return name;
    }

    /// <summary>
    /// Implements the interface because the primary function is internal.
    /// </summary>
    string IContentStream.GetFormName(XForm form)
    {
      return GetFormName(form);
    }

    /// <summary>
    /// The PdfFormXObject gets invalid when PageNumber or transform changed. This is because a modification
    /// of an XPdfForm must not change objects that are already been drawn.
    /// </summary>
    internal PdfFormXObject pdfForm;

    internal XGraphicsPdfRenderer pdfRenderer;
  }
}